1.An alert fires for multiple failed logins followed by a success. What now?
Practice this with AIShow model answer
Treat the sequence as a hypothesis of account compromise, not proof. Confirm that failures and success concern the same identity, application and relevant time window; shared proxies can make unrelated users appear together. Examine authentication results, MFA details, device context and session activity after success. Compare with approved access patterns without treating familiar locations as automatically safe. Password mistakes are plausible, but unexpected privilege changes or downloads raise concern. Preserve the events and escalate proportionately. Revoke sessions or restrict the account only under documented authority, balancing rapid interruption against locking out legitimate business access.
Worked example: In an owned identity lab, deliberately mistype a test account password before signing in correctly. Expect failures followed by success; compare device and session context to explain why the sequence alone does not establish compromise.
- Preserve the alert and underlying authentication events with timestamps and time zones.
- Match identity, application, source and session fields; inspect MFA and device context.
- Review subsequent account changes and resource access, recording visibility gaps.
- Escalate with confidence and scope; apply only authorised session or account restrictions.
Common mistake: Blocking a shared source IP immediately can disrupt many users while leaving an attacker's existing authenticated session active.
Follow-up: Which post-login activity would make you escalate this sequence even when MFA succeeded?
- NIST SP 800-61 Rev. 3: Incident ResponseFinal · April 2025; supersedes Rev. 2
- Microsoft Entra sign-in logsLiving vendor documentation